This invention relates to a highwall mining system of the type wherein multiple conveyor cars are connected together to form a conveyor train which extends into a seam being mined by a mechanical miner located at the inner end of the conveyor train.
It is well known that high wall mining systems enable relatively efficient mining of near surface coal seams with a reduced cost of excavation, high yield, and reduced environmental damage.
Under highwall methodology the surface is excavated to the level of the coal seam as with a typical surface mine. A vehicle, sometimes typically referred to as a xe2x80x9claunch vehiclexe2x80x9d is set in place adjacent to the exposed wall of the seam and on the same inclination angle as the seam. From the launch vehicle, a mining apparatus (hereafter called a xe2x80x9cminerxe2x80x9d) is launched into the seam. The miner used in typical high wall operations is similar or identical to equipment which is employed in traditional underground coal mines, and includes a cutter apparatus which moves up and down the coal face. Conveyor sections carry the cut coal from the miner to the launch vehicle. Propulsion cylinders contained in the launch vehicle push the mining apparatus horizontally into the coal seam and withdraw the apparatus once mining is complete. As the mining equipment proceeds into the seam, conveyor sections are added which, as noted above, convey the coal back from the miner to the launch vehicle from where it is conveyed elsewhere in the mine. The miner may penetrate the seam for a length up to approximately 1000 feet.
A key element of highwall mining is that no personnel are required to enter the coal seam. It is important that the mining operation be completed and the equipment withdrawn quickly as no roof support is employed. Video imaging of the mining operation is typically maintained by a series of cameras in the area of the miner, which is viewed by the operators at the launch vehicle. When the miner is in operation, a series of cables extend from the launch vehicle into the mining apparatus and the conveyors. The vertical reach of the cutters on the mine varies, depending upon the size of the miner.
There are a variety of highwall mining systems currently on the market, some of which have been reasonably successful while others have been less so. It appears that few, if any, of the current available systems are effective in mining seams having relatively high slopes, e.g. slopes up to about 30xc2x0.
Consequently, there is a need for a highwall mining system capable of effective operation in steep dip seams, e.g. up to about 30xc2x0.
The existing prior art systems are also, in general, relatively cumbersome to move from one location to another. Often, relocation requires substantial dismantling of these complex systems over a time span of several days. Consequently, there is a need to provide a transportable highwall mining system which can be disassembled, moved, and reassembled by personnel in a matter of hours.
It is a general objective of the invention to provide an improved highwall mining system capable of alleviating the several problems briefly noted above.
A highwall mining system particularly suitable for steep dip seams and of the type wherein multiple conveyor cars are connected together to form a conveyor train which extends into a seam being mined in accordance with one aspect of the invention comprises:
(a) an elongated launch vehicle having a launch deck for receiving and supporting a conveyor car which is to be added to or removed from an outer end of the conveyor train when in operation, said launch deck having a conveyor belt running lengthwise thereof and extending to an aft end of said launch vehicle;
(b) a plurality of conveyor cars forming the conveyor train and adapted to convey mined material outwardly to the conveyor belt of said launch deck;
(c) a miner attached to an inner end of said conveyor train for cutting material from the seam being mined and moving it to the inner end of the conveyor train for conveyance by the latter outwardly to said launch deck; and
(d) a pair of extendible support columns secured to an aft end portion of said launch deck in flanking relation thereto and having hydraulic cylinders associated therewith to effect controlled lifting and lowering of said aft end of the launch deck and to tilt the latter in a vertical plane as desired to accommodate the dip angle of the seam to be mined.
A further pair of extendible support columns is preferably secured to a forward end portion of said launch deck in flanking relation thereto and having hydraulic cylinders associated therewith for effecting controlled lifting and lowering of the forward end portion to effect substantial alignment of the launch deck with an exposed face of the seam.
The support columns at the aft end of the launch deck are preferably pinned to opposing sides of said launch deck aft end portion to allow pivotal motion of said support columns relative to said deck, said launch vehicle having stops to limit the degree of said pivotal motion of the aft end support columns.
The launch deck may advantageously be further equipped with a pair of laterally spaced stabilizing cylinders each located at the forward end of the deck in alignment therewith and capable of being extended forwardly of said deck and into engagement with parts of the highwall formation being mined to assist in securing and stabilizing the launch vehicle during operation.
Skid tracks may be located below the lower ends of both the forwardly and the rearwardly located pairs of support columns, each skid track extending laterally of the launch deck and adapted to be supported on the earth when in use, and an elongated skid cylinder connected between each skid track and an associated lower end of each pair of support columns such that either or both of the fore and aft ends of the launch vehicle can be shifted laterally and the launch vehicle angularly adjusted as desired in a horizontal plane.
The lowermost ends of said support columns preferably each have a foot mounted thereto via a pivot pin extending parallel to the associated skid track such that forces on said launch vehicle tending to displace the latter rearwardly cause said feet and said tracks to tilt slightly and dig in to the earth to resist movement.
A highwall mining system particularly suitable for steep dip seams and of the type wherein multiple conveyor cars are connected together to form a conveyor train which extends into a seam being mined in accordance with a further aspect of the invention comprises:
(a) an elongated launch vehicle having a launch deck for receiving and supporting a conveyor car which is to be added to or removed from an outer end of the conveyor train when in operation;
(b) said launch deck having a conveyor belt running lengthwise thereof to receive mined material which has been transported along the conveyor train and to convey and discharge said material from the rear or aft end of the launch vehicle;
(c) a miner for cutting material from the seam being mined and moving it to an inner end of the conveyor train;
(d) a plurality of conveyor cars connected end to end to define said conveyor train and extending, when in use, from said miner at an inner or front end of the train rearwardly to a last conveyor car on said launch deck, each conveyor car having a powered conveyor belt with said belts of the cars in the conveyor train being in closely adjacent relation to each other to provide continuity of conveyance of the mined material for discharge thereof onto the conveyor belt of the launch deck;
(e) a pair of elongated hydraulic conveyor car drive cylinders mounted to said launch deck in parallel relation to a last said conveyor car when supported on said launch deck, said conveyor car drive cylinders each including a ram having activatible conveyor car engaging devices thereon such that actuation of said drive cylinders in conjunction with said engaging devices causes said conveyor cars to be advanced into a seam being mined or to be retraced therefrom as desired.
In a preferred embodiment each of said conveyor cars has engagement lugs on opposing sides thereof each said lug having a socket therein, said conveyor car engaging devices on the rams of said drive cylinders including male pin members adapted to enter said sockets of the engagement lugs of the last conveyor car on said launch deck to enable transmittal of forces from said drive cylinders via said engagement lugs to said conveyor car and thence to the entire conveyor train; and an actuator associated with each of said male pin members to effect their advancement into said sockets of the lugs and withdrawal therefrom whereby as said drive cylinders are advanced and retracted said conveyor train is advanced or retracted as desired.
The launch deck further preferably includes a staging cylinder having a ram movable into and out of engagement with the last conveyor car of said train to assist in effecting any desired motion of same lengthwise of said deck in the course of loading and unloading of the conveyor cars to and from said deck to facilitate connecting said last conveyor car to the next adjacent conveyor car or disconnecting same.
Stop cylinders may be mounted to said launch deck and capable of being advanced into engagement with a next-to-last conveyor car of the conveyor train to prevent unwanted motion of the train back into a sloping seam at those intervals of time when said conveyor car engaging devices are not engaged with said next-to-last car.
A transportable launch vehicle for a highwall miner having multiple elongated conveyor cars that may be connected together to form a conveyor train, in accordance with a further aspect of the invention comprises:
(a) an elongated launch deck for receiving and supporting a conveyor car which is to be added or removed from an end of the conveyor train when in operation;
(b) an upper equipment deck disposed, in use, in connected and spaced relation above said launch deck;
(c) fore and aft pairs of extendible support columns secured to said launch deck in flanking relation thereto and having hydraulic cylinders associated therewith for tilting and changing the elevation of the entire launch vehicle as required to accommodate the dip angle and location of the face of a seam to be mined;
(d) fore and aft pairs of outrigger legs attached to fore and aft end portions of said upper deck for temporarily supporting the latter above said launch deck such as to allow the launch deck to be removed from beneath said upper deck for transport purposes;
(e) said outrigger legs being extendible and retractable such that after removal of the launch deck, and on retraction thereof, said upper deck may be lowered onto a suitable transport device, said outrigger legs being removed during transportation and, following transport to a desired location, the outrigger legs may be reattached and extended to raise said upper deck thus allowing said launch deck to be again relocated therebeneath and reconnected in said spaced relation thereto.
Preferably said fore and aft pairs of support columns are detachable from said upper and launch decks respectively to permit ready transport of said decks.
Still further said launch deck may be provided with detachable wheel and axle sets to permit the launch deck to be towed away from beneath the upper deck.
In a preferred embodiment, uprights are connected between said upper and launch decks for securing them in said spaced relation during normal use. When the outriggers are in place and extended they provide temporary support to the upper deck and allow it to be lowered downwardly.
A further aspect of the invention provides a method of conversion between transport and operating modes of a transportable launch vehicle for a highwall miner of the type having multiple elongated conveyor cars that may be connected together to form a conveyor train, wherein said launch vehicle comprises an elongated launch deck for receiving and supporting a conveyor car which is to be added or removed from an end of the conveyor train when in operation, and an upper equipment deck fixed, in use, in spaced relation above said launch deck; said method comprising:
(a) providing fore and aft pairs of extendable and retractable outrigger legs at fore and aft end portions of said upper deck for temporarily supporting the latter above said launch deck;
(b) disconnecting the upper deck from the launch deck;
(c) removing the launch deck from beneath said upper deck for transport purposes when said legs are in an extended condition;
(d) retracting said outrigger legs to lower said upper deck downwardly onto a suitable transport device;
(e) transporting said decks to a desired location;
(f) extending said outrigger legs to raise said upper deck; and
(g) positioning said launch deck beneath said upper deck and reconnecting the decks in said spaced relation.
In the preferred form of the invention the outrigger legs are removed prior to step (e) above and reattached after step (e).
The method may include providing said launch deck with detachable wheel and axle sets to permit the launch deck to be towed away from beneath the upper deck.
When said outriggers are in place they provide temporary support to the upper deck when the launch deck is being removed from or positioned beneath said upper deck. The outriggers are normally removed prior to the start of actual mining operations.
Further features and advantages of the invention will be apparent from the following description and the appended claims.